Monitoring and Managing vFabric EM4J

You can monitor virtual machine memory utilization, including
ballooning, using vSphere Client or other tools such as esxtop.
More specific information about EM4J ballooning is available by querying
EM4J MBeans through JMX. The vSphere Web Client EM4J plug-in adds additional
monitoring capabilities to the vSphere Web Client, including detailed
real-time and historical metrics for EM4J-enabled Java workloads. The
vSphere Web Client EM4J plug-in is also useful for monitoring memory usage
in virtual machines that are not running EM4J-enabled Java workloads.

The EM4J plug-in is distributed in separate versions that are
compatible with vSphere 5.0 and vSphere 5.1. The monitoring information
presented by the plug-in is the same for both versions, but due to the
redesign of the vSphere Web Client in 5.1, the procedure for accessing the
information is different for the two versions.

Monitoring Memory with vSphere Client

Using vSphere Client, you can observe ESXi memory management as
different ESXi memory management techniques are applied and memory is
recovered from the VMs. Charts on the Performance tab let you view the memory metrics
over time. You can see how memory utilization responds to different loads
and events and how you might arrange and configure VMs to more fully
utilize the physical resources and maintain desired performance.

You can select an individual VM, as illustrated by the following
example, a Resource Pool, or the entire host. Choose the Performance tab and select Memory from the Switch
to drop-down list. If necessary, click Chart Options... and select Balloon and Balloon
target in the Counters
section.

The balloon metrics in the vSphere Client do not distinguish between
the VMware tools balloon and the EM4J balloon, but the balloon in any
given VM must be one type or the other. When EM4J is enabled in a VM, the
Balloon and Balloon target metrics for that VM describe the current and
target sizes of the EM4J balloon. When EM4J is not enabled, these metrics
instead describe the VMware tools balloon driver. When you view a group of
VMs, the numbers from both types of balloons are summed.